Just search what you want on the internet and find a way to edit it in Photoshop or premiere or whatever. Honestly it's just about how creative you can get with it, doesn't take much. The clip you used for the example just looks like a slo mo of a ride in the snow.

I've also seen some anime edited gifs used for lofi mixes, they're really creative. Just start with an idea and edit it to your liking I guess.